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86 Cards in this Set
- Front
- Back
Ecosystem |
Consists of all the organisms living in a community as well as the abiotic factors with which they interact |
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Two main processes in an ecosystem |
1. Energy Flow: autotrophs convert in organic carbon into organic carbon that the heterotrophs can use. 2. Chemical Cycling: Includes nitrogen and phosphorus cycles |
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1st law of thermodynamics |
energy is transferred not created nor destroyed |
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2nd law of thermodynamics |
every exchange of energy increases the entropy of the universe |
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Conservation of Mass |
matter cannot be created nor destroyed |
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Detrivores |
(Decomposers) They derive energy from detritus, nonliving organic matter |
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Primary Production |
The amount of energy created by the primary producers (autotrophs) This sets the energy "spending" limit for an ecosystem |
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Gross Primary Production (GPP) |
Total energy produced by vegetation via photosynthesis (measured over a period of time) |
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Net Primary Production (NPP) |
NPP= GPP - autrophic respiration This calculates the amount of new biomass available to consumers |
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Net Ecosystem Production (NEP) |
Measures the total biomass accumulation during a given period. This is computed by measuring the net flux between CO2 and O2 |
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Factors that control primary production |
Light and Nutrients |
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Limiting Nutrient |
An element that must be present in order to achieve primary production. Aquatic ecosystems require nitrogen and phosphorus |
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Redfield Ratio |
C: 106, N:16, P:1 (Optimal nutrients needed for algae growth) |
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eutrophication |
loading of nutrients into a system that results in algae production |
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cultural eutrophication |
eutrophication caused by humans |
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Limiting Element for cynobacteria blooms |
phosphorus |
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Lake Atitlan |
An oligotrophic lake that began experiencing harmful cynobacteria blooms due to hurricanes destroying water treatment plants, people pumping their waste into the water |
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What affects primary production in terrestrial ecosystems |
higher temperature and higher moisture creates higher primary production |
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evapotranspiration |
plant transpiration and evaporation from landscape. Is affected by precipitation, temperature and sunlight. |
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Nutrients that limit the soil |
1. Young soil limited by nitrogen 2. Old soil limited by phosphorus |
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Plants get nutrients from... |
nitrogen fixing bacteria, mycorrhizal fungi, root hairs on plant roots, and many plants release enzymes that increase the availability of limiting nutrients |
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Secondary Production |
Amount of chemical energy in food converted to new biomass during a given period of time. |
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Production Efficiency |
(Net secondary production)/(assimilation of primary production) times by 100. Shows how well certain species are at converting food into energy. Insects have higher production efficiency compared to birds and mammals. |
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Trophic Efficiency |
The percentage of production transferred from one trophic level to the next. It's about 10%. |
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Turnover Time |
(Standing Crop Density)/ (Production Density/day) |
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Decomposition Rates |
1. Determined by temperature, moisture, and nutrient availability 2. Rapid Decomposition results in more productive ecosystems which caused there to be less nutrients in the soil. |
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Carbon Cycle |
Phosynthesis fixes inorganic carbon into carbon, fossil fuels bring stored carbon into the environment |
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Nitrogen Cycle |
Main reservoir is the atmosphere, some bacteria including cyanobacteria can fix nitrogen gas. |
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What happens to Nitrogen in anaerobic conditions |
We get denitrofication. (NO3- becomes N2 gas) |
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Aquatic Environments (cyanobacteria) are most often limited by... |
phosphorus (Although they are limited by nitrogen too) |
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Interspecific Interactions |
Interactions between different species
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Competition |
(-,-) Occurs when two species compete for the same resource |
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Competitive Exclusion |
Local elimination of a compering species (This occurs often) |
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Fundamental Niche |
The niche that can potentially be occupied by a a certain species |
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Realized Niche |
the niche actually occupied by a certain species |
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Leibig's Law of the Minimum |
There are always limiting resources that prevents uncontrollable growth |
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Resource Partitioning |
Species that occupy different niches exploit different resources |
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Character Displacement |
When species with similar traits occupy the same region, their differences will be more pronounced than if they did not live in close proximity to each other. |
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Predation |
(+,-) One organism kills the other for food |
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Prey Adaptations |
1. Cryptic Coloration: Camouflage 2. Aposematic Coloration: Bright Colors convey that a prey is poisonous 3. Batesion Mimicry: A harmless species mimic a harmful species 4. Mullerian Mimicry: two unpalatable species mimic each other |
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Herbivory |
(+,-) Refers to interactions in which herbivores eat parts of a plant or algae. Some plants have evolved ways to prevent this. |
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Symbiosis |
Situation where two or more species live in direct and intimate contact with one and other. |
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Parasitism |
(+,-) Interaction where the parasite derives its nourishment from its host. More dense populations have higher parasitism burden. |
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Mutualism |
Both species are positively affected. Example: Bull horn acacia trees and ants. The tree provides shelter and the ants protect the tree from other pest. |
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Commensalism |
(+,o) One species benefits the other one isn't affected. Examples: Whales and Barnacles. |
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Facilitation |
(+,+) or (o,+) Is an interaction in which one species has positive effects on another species without direct and intimate contact. Example: beaver's making a dam. |
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Species Diversity |
Variety of organisms from different species that make up the community. |
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Species Richness |
The number of different species in a community |
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Relative Abundance |
How abundant a species is in an environment |
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Shannon Diversity Index (H) |
Shows how diverse an area is. The highest amounts of diversity exists around a pH of 7. Communities with a higher biodiversity are more stable. |
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Trophic Structure |
Feeding relationships between organisms in a community. |
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Food Chains |
Link trophic levels from producers to top predators |
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Food Web |
A branching food chain with complex trophic interactions |
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Dominate Species |
Highly Abundant Species because they are most successful at getting resources and avoiding predation. |
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Keystone Species |
Have a unique pivotal role in the community. (Doesn't have to be positive or abundant) Example: Starfish in the tide poos in California |
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Ecosystem Engineers |
Foundation Species that cause physical changes in the environment. Example: Beavers with their dams |
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Bottom-Up Model |
Proposes a unidirectional influence from low to higher trophic levels |
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Top-Down Model |
Trophic cascade model. Proposes that control comes from the top. |
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Biomanipulation |
Deliberate altering of an ecosystem by adding or removing species. Used to improve water quality in polluted lakes |
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Disturbance |
Any event that changes a community |
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Intermediate Disturbance Levels |
A community that experiences some disturbances but not a crazy amount. Provides the highest amount of species richness. |
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ecological succession |
the sequence of community and ecosystem changes after a disaster |
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Primary Succession |
Occurs when vegetation or microorganism colonize a piece of land that hasn't had any life. Occurs after big disturbances like glacier receding. |
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Secondary Succession |
When vegetation or microorganism colonize an area that has recently experienced a disturbance but had like there prior to the disturbance. |
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Species Area Curve |
When all other factors are help constant, larger geographic areas have more species |
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Lake Tahoe clarity driven by... |
small watershed to lake ratio |
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paleolimnology |
looks at the record of fresh water lakes by studying the bottom core of sediment at the bottom of the lake. (Tahoe has a lot of Iron in top layer) |
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Air Pollution's affect on Tahoe |
Inversion in the atmosphere causes pollutants to settle in the lake |
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Reasons Water Quality is Declining |
Historically: Lumber Removal Intermediate Years: The lake recovered Recent Years: Air Pollution, lake warming, and the loss of wetlands (tahoe keys), cultural eutrophication |
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Fate of endemic Species in Tahoe |
72% of invertebrates in the benthic zone have disappeared, tahoe has 10 endemic species that are at risk because of invasive species |
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Legal Introduction of Invasive Species (In Tahoe) |
Lake Trout was introduced so people could get larger fish, mysid shrimp were also introduced and ate all the filtering zooplankton |
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Illegal Introduction of Invasive Species (In Tahoe) |
Asian Clams (excrete feces that make good conditions for algae growth), Invasive plants (make good habitats for invasive species), Bass another big fish |
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Culural Imperialism |
When people bring species from there home to make their new home like their old one. |
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Climate |
Statistical averages (weeks, decades) Over a 30 year period. |
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Deviation |
Anomalies from the average |
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Climate Change |
can mean change up or down in various variable including precipitation and temperature. |
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Climate Forcing |
When an event causes climate change like El nina or El nino |
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Eocene |
A global warm period about 50 million years ago |
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Predicted Future Climate (Globally) |
1. Change will be greatest towards to poles 2. There will probably be global changes in precipitation
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Climate Change Effects (Sierra Nevada) (Good understanding) |
1. Less Mountain Snow 2. Less water to go around in the summer 3. Increased drought, changes in vegetation 4. Increased need for management |
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Climate Change Effects (Globally) (Good Understanding) |
1. Sea level rises 2. Ecosystem change 3. Melting of the polar ice 4. Coral Reefs disappear |
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Climate Change Effects (Sierra Nevada) (Medium Understanding) |
1. Changes in how well forest grow 2. Increased habitat for invasive 3. Shifts in Farming crops |
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Climate Change Effects (Globally) (Medium understanding) |
1. Increase intensity of hurricanes 2. Increase drought in some places 3. Increase in rain/ snow in some places |
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Climate Change Effects (Low understanding) |
How will people and ecosystems react to the change |
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Affects of Global Warming on Agriculture |
1. More extreme weather 2. Loss of farm land new coasts 3. Increased amount of pests 4. Loss of biodiversity |
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How climate change will affect health |
Disease will spread more. Examples: Malaria, West Nile, and Lyme Disease |